The CEO of Fannie Mae -- which buys mortgages from lenders and sells them to investors on the secondary mortgage market -- has announced he is stepping down once a replacement is named, several news reports have said.

Here are a few nuggets from his keynote speech at a real estate conference put on by the University of San Diego at the Hilton San Diego Bayfront:

--Williams said: "Our company is preparing for change. As the policymakers consider how to reform the housing market, we expect vigorous debate on all sides of the issue."

--Someone asked about possibility of Fannie Mae being privatized. Williams said: "We're not engaging on providing options to the market." He said Fannie Mae is asking policymakers to ask key questions during the process of figuring this out. He continued: "We remain focused on how to serve the market during this period of transition to make sure we're building value for he company but also for the taxpayer."

--Williams outlined a series of questions that policymakers should ask in deciding the future of the mortgage market in the U.S. that included: What is the role of the 30-year fixed rate for the future?

Fannie Mae is a government-sponsored enterprise whose connection with subprime mortgages caused its downfall and eventually led government take-over. Williams, a longtime housing executive, was appointed CEO of Fannie in April 2009, following the take-over.